Wednesday, December 3, 2014

week 5

In week 5, I have learned some basic structure of proof, it is my first time to use that kind of structure to proof something. This is the most difficult part of this week, I have to memorize the structure of proof, also I have looked through my assignment 1 which is hard for me. The biggest thing is term test in this week. Over all, the term test is easier than assignment 1, and I think I did well in this term test

week 4

In week 4, I have learned some basic rule of negation, combing the understanding of week 3, it become much easier to negate a sentence, there are three steps of negation sentence. Firstly, we need to change sentence to symbolic form, next we use basic rule to negate the symbolic form, at last, we change the symbolic form to sentence. I found out that this way is quicker to negate sentence and it has high accuracy. Besides that, I have learned another symbol which mean imply, I think it similar to and, but there are some difference between them. Imply mean there is cause and consequence.

week 3

In this week, I have learned conjunction,disjunction, and negation. I was familiar with conjunction and disjunction which I have learned in my high school. The problem is negation, at first I did not get how to negation some sentence, I have no idea which part of sentence should be negated. There is a example  all employees earning over 110000 are female. In this example, I have no idea how to change all employee. At the end of lecture, I have learned a new skill to negate that kind of sentence. All I need is changing the sentence to symbolic form, and then the problem become directly and easy to solve

Friday, September 19, 2014

week2


                                                            CSC165H1 week 2

In this week, we mainly focused on quantifiers, sentences and logical connectives.During this week, the core concept was logic. understanding of logic is usefel for finding out the structure of the sentences which would be favouirng studying for the lecture material of this week.
When the big idea of logic was introduced in lecture, I was confused since it required lots of analysis and understanding of the sentence structure.After the structure was understood, the elements in the set can then be found. After some practices and examples, I was able to understand the logic better, which is quite excited to me since it was the frist difficulty in my campus study xperience. I enjoyed the process to solve the problem a lot.
There are some examples which help a lot:
1 def q0(S1,S2):
    return not all({x in S2 for x in S1})
2 def q1(S1,S2):
   return any({x in S2 for x in S1})
In example 1 if there is any element in S2 not in S1, the statement is true, otherwise it is false. In example 2 if there is any element in S2 containing in S1, the statement is true, if all the elements in S2 are different from S1, the statement is false.